No association between polymorphisms and haplotypes of COL1A1 and COL1A2 genes and osteoporotic fracture in postmenopausal Chinese women

Collagens and elastin genetic variations and their potential role in aging-related diseases and longevity in humans

Collagens and elastin are 'building blocks' of tissues and extracellular matrix. Mutations in these proteins cause severe congenital syndromes. Adverse genetic variations may accelerate the aging process in adults contributing to premature morbidity, disability and/or mortality. Favorable variants may contribute to longevity and/or healthy aging, but this is much less studied. We reviewed the association between variation in the genes of collagens and elastin and premature aging, accelerated aging, age-related diseases and/or frailty; and the association between genetic variation in those and longevity and/or healthy aging in humans. A systematic search was conducted in MEDLINE and other online databases (OMIM, Genetics Home Reference, Orphanet, ClinVar). Results suggest that genetic variants lead to aging phenotypes of known congenital disease, but also to association with common age-related diseases in adults without known congenital disease. This may be due to the variable penetrance and expressivity of many variants. Some collagen variants have been associated with longevity or healthy aging. A limitation is that most studies had <1000 participants and their criterion for statistical significance was p < 0.05. Results highlight the importance of adopting a lifecourse approach to the study of the genomics of aging. Gerontology can help with new methodologies that operationalize biological aging.

Sp1 Binding Site Polymorphism at COL1A1 Gene and Its Relation to Bone Mineral Density for Osteoporosis Risk Factor Among the Sikkimese Men and Women of Northeast India

Single nucleotide polymorphism in the first intron of Collagen type I alpha 1 (COL1A1) gene which is the binding site of specificity protein 1 (Sp1) transcription factor associated with low bone mineral density and osteoporosis. To evaluate such genetic factors among the Sikkimese population, a total of 150 cases (75 men and 75 women) with primary osteopenia and osteoporosis and 150 healthy controls (75 men and 75 women) of age range between 35 and 65 years were enrolled in this study. The COL1A1 genotypes [SS, Ss and ss] were assessed by restriction enzyme [MscI] digestion of DNA after amplification by polymerase chain reaction. There, only 2.7% women and 1.3% men cases had restriction site with heterozygous genotype (Ss) and no homozygous genotype (ss) were detected. There was no statistically significant association between low bone mass and genotypes on analysis (χ² = 1.014, P = 0.314; RR = 1.510) that, the Sp1 binding site polymorphism at the COLIA1 gene is very rare and has no contribution in the development low bone mineral density.

Fibroblast Growth Factor 21 Is Associated With Bone Mineral Density, but not With Bone Turnover Markers and Fractures in Chinese Postmenopausal Women

Fibroblast growth factor 21 (FGF21) is a member of the endocrine FGF subfamily and an important metabolic regulator that has multiple beneficial effects on glucose homeostasis and lipid metabolism. However, it was unclear whether FGF21 would induce bone defects in humans. This study evaluated the associations of FGF21 levels, bone mineral density (BMD), osteoporotic fracture, and bone turnover marks (BTMs) in postmenopausal women. A total of 1342 postmenopausal Chinese Han women (511 cases of fragility fracture in the case group and 831 cases in nonfragility fracture group) were enrolled. Serum FGF21 concentration was measured by ELISA (Quantikine), serum calcium (Ca), phosphate (P), alkaline phosphatase, 25-hydroxyvitamin D, parathyroid hormone, β-crosslinked C-telopeptide of type l collagen, were measured using an automated Roche electro-chemiluminescence system. BMD was measured using dual-energy X-ray absorptiometry. The association with age, BMD, 25-hydroxyvitamin D, parathyroid hormone, β-crosslinked C-telopeptide of type l collagen, and FGF21 levels were also evaluated in postmenopausal women. In nonfracture group and fragility fracture group, postmenopausal women's FGF21 level was 226.57pg/mL (149.11-354.43 pg/mL) and 219.43pg/mL (147.21-323.74 pg/mL), respectively. There is no significant difference in serum FGF21 levels between the fragility fracture group and the nonfracture group (p = 0.160). There was a significant statistical difference in BMD between the fragility fracture group and the nonfracture group (p = 0.000). In multiple linear regression analysis, FGF21 levels were significantly positive associated with lumbar BMD in postmenopausal women (L1-4, p = 0.007), independent of other factors, especially in fragility fracture group (L1-4, p = 0.001). In addition, a significant positive association was also observed between serum FGF21 levels and age in postmenopausal women (p < 0.05). We reveal a positive correlation between serum FGF21 concentrations with lumbar BMD in Chinese Han postmenopausal women. No significant correlations are present between serum FGF21 and bone turnover marks or serum FGF21 and fragility fracture in our study.

Insertion/deletion polymorphism in the 3' untranslated region of COL1A2 disrupts its interaction with microRNA-382 and leads to decreased susceptibility to osteoporotic fracture

A growing body of evidence has proved that the expression of COL1A2 is associated with a reduced risk of osteoporotic fracture. One single-nucleotide polymorphism (rs3917) located within the 3'-untranslated region of COL1A2 may "alter" binding site of miR-382 and thereby associated with the risk of osteoporotic fracture. Bioinformatic analysis, luciferase reporter assay, site-directed mutagenesis, Western blot and real-time PCR were performed in this study. In this study, we validated COL1A2 as a target of miR-382 in osteoblast. In addition, bone tissue samples were genotyped as wild-type rs3917, heterozygous rs3917, and homozygous rs3917. The expression of miR-382 was comparable between the genotype groups, whereas the expression of COL1A2 mRNA and protein was much higher in heterozygous rs3917 and homozygous rs3917 than the wild-type rs3917 group. Furthermore, we transfected the wild-type rs3917 and heterozygous rs3917 cells with miR-382 mimics or inhibitors and found that the transfection with miR-382 mimics significantly increased the level of the miR-382 in the cells of both genotypes, and the introduction of miR-382 inhibitors substantially suppressed the level of miR-382 in both cells. In wild-type rs3917 cells, transfection of miR-382 mimics and COL1A2 small interfering RNA (siRNA) similarly and substantially downregulated the expression of COL1A2, while in heterozygous rs3917 cells, only COL1A2 siRNA notably reduced the expression of COL1A2, whereas introduction of miR-382 mimics left expression of COL1A2 intact. The findings showed rs3917 polymorphism interfered with the interaction between COL1A2 mRNA and miR-382, and minor allele is associated with a reduced risk of osteoporotic fracture.

Association between vitamin D receptor gene polymorphisms (Fok1 and Bsm1) and osteoporosis: a systematic review

Osteoporosis is a health concern characterized by reduced bone mineral density (BMD) and increased risk of fragility fractures. Many studies have investigated the association between genetic variants and osteoporosis. Polymorphism and allelic variations in the vitamin D receptor gene (VDR) have been found to be associated with bone mineral density. However, many studies have not been able to find this association. Literature review was conducted in several databases, including MEDLINE/Pubmed, Scopus, EMBASE, Ebsco, Science Citation Index Expanded, Ovid, Google Scholar, Iran Medex, Magiran and Scientific Information Database (SID) for papers published between 2000 and 2013 describing the association between Fok1 and Bsm1 polymorphisms of the VDR gene and osteoporosis risk. The majority of the revealed papers were conducted on postmenopausal women. Also, more than 50% studies reported significant relation between Fok1, Bsm1 and osteoporosis. Larger and more rigorous analytical studies with consideration of gene-gene and gene-environment interactions are needed to further dissect the mechanisms by which VDR polymorphisms influence osteoporosis.